It is becoming increasingly important to provide certain equipment with a pressure supply connection and also to provide other apparatus with an electrical connector as well as with a pressure supply connection in order to be able to monitor and control the operating processes or pressure changes which occur in the equipment or apparatus. For example, a pressure supply connection and an electrical connector coupler are required in a suspension system for motor vehicles having a level adjustment and/or height control apparatus. The apparatus is used to determine the actual distance between the vehicle axle and the vehicle frame and is electrically or electronically operated by apparatus which is internally located in the pressure chamber of the suspension elements or the dampening springs.
Such an arrangement requires a pressure-tight lead-in coupler for accommodating the electrical contacts and pressure lines which extend from the pressure chamber to the atmosphere. However, the design of such a coupler not only is difficult but also is expensive due to the limited amount of space that is available.